The influence of fasting and carbohydrate-enriched drink administration on body water amount and distribution: a volunteer randomized study

BACKGROUND: Fasting prior to anesthesia is considered aspiration prophylaxis. However, prolonged food and drink restrictions may increase the risk of other complications. The aim of this study was to assess whether a carbohydrate-enriched drink (Nutricia™ preOp®), recommended by the enhanced recovery after surgery (ERAS) protocol, can improve body hydration in fasting healthy individuals. METHODS: Measurements were done with the bioelectric impedance analysis with a Fresenius body composition monitor. Body composition, total body water, water distribution, and hemodynamic parameters were measured at the beginning of the study and after 10 h and 12 h of fasting. Patients fasted for 10 h and then were divided into two groups: the control (n = 40) and the pre-op group (n = 41). The pre-op group received 400 mL of Nutricia™ preOp®, as suggested in the ERAS guidance. The two-tailed Student’s t test was used to compare two groups with normally distributed data and homogenous variances; if variances were heterogeneous, Welch’s test was used. The Mann-Whitney U test was used to compare two groups with non-normal data distribution. p < 0.05 was considered statistically significant. RESULTS: We found no significant differences between the control and pre-op groups regarding body water distribution and body composition. We did not observe significant losses in the total body water after fasting. Also, blood pressure was not affected by fasting. CONCLUSION: We have proven that pre-op did not impact either body composition or body water. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04665349. Registered on 11 December 2020—retrospectively registered.